Apparatus for stamping indicia on materials

Abstract

In a marking system for stamping materials such as aluminum strip, a pulse of determined energy is supplied to a solenoid, to impart a determined kinetic energy to a die. The die is guided to dissipate substantially all of this kinetic energy in the deformation of the material being stamped. The pulse of energy applied to the solenoid may be controlled by a programmable computer, programmed to control the duration of time that a current is applied to the solenoid. The computer may control a plurality of such solenoids, controlling the times and relative numbers of operation of each of the solenoids.

What is claimed is: 
     
       1. A marking system for stamping indicia marks into the surface of thin sheet material, comprising: a platform having a surface for supporting and transporting said sheet material thereon, said sheet material being loosely guided;   a die with a raised marking at one longitudinal end thereof, said die being mounted for longitudinal motion in a direction transverse to said platform surface, said marking facing said platform surface;   an armature mounted for motion in said transverse direction, said armature being in contact with the other longitudinal end of said die;   means for moving said armature toward said surface from a standby position, said armature driving said die against said sheet material, said die flying ballistically toward said material to inelastically deform said material and being stopped only by said sheet material being pressed against said platform surface upon impact by said die, said means for moving including means for imparting a predetermined longitudinal kinetic energy to said die of a magnitude sufficient, without substantial excess, to provide said inelastic deformation.   
     
     
       2. A marking system as claimed in claim 1 and further comprising a solenoid, said armature being an element of said solenoid, said armature driving said die upon energization of said solenoid. 
     
     
       3. The marking system of claim 2 further comprising spring means for resiliently biasing said die to abut said armature. 
     
     
       4. The marking system of claim 2 wherein said means for imparting a predetermined kinetic energy to said die further comprises means for applying a pulse of determined energy to said solenoid. 
     
     
       5. The marking system of claim 4 wherein said means applying pulses to said solenoid energizes said solenoid with a duty cycle of less than 2% with power dissipation during on-time at least ten times the rated continous power dissipation. 
     
     
       6. The marking system of claim 2 wherein said die is positioned from 0.01 inches to 0.2 inches from said material before energization of said solenoid. 
     
     
       7. The marking system of claim 6 wherein said die is positioned from 0.06 to 0.09 inches from said material before said solenoid is energized. 
     
     
       8. The marking system of claim 2 wherein said die is positioned to accelerate to substantially maximum velocity, upon energization of said solenoid, before it impacts said material. 
     
     
       9. A marking system for stamping strips of a material, comprising a row of a plurality of solenoids each mounted to drive a separate die, means for guiding said strip for movement in alignment with said row spaced from said dies, and control means for selectively applying electrical pulses of determined energy to said solenoids to impart kinetic energy to the respective dies, said dies being guided to impact said material and dissipate substantially all of said kinetic energy in deforming said material, the indicia on the dies, to be stamped in said material, having substantially equal line lengths and the energy of the pulses applied to each of said solenoids being substantially equal. 
     
     
       10. The marking system of claim 9 wherein said control means comprises means applying pulses to said solenoids with a duty cycle of less than 2% and a power dissipation during ontime at least ten times the rated continuous power dissipation of the solenoids. 
     
     
       11. The marking system of claim 10 wherein said control means comprises a programmable source of said electrical pulses. 
     
     
       12. A marking system for stamping indicia marks into the surface of thin sheet material, comprising: a platform having a surface for supporting and transporting said sheet material thereon; said sheet material being loosely guided relative to said surface;   a plurality of dies arranged in a row, each said die having a raised marking at one longitudinal end thereof, each said die being mounted for longitudinal motion in a direction transverse to said platform surface, said marking facing said platform surface;   means for guiding said strip for movement in alignment with said row and spaced from said dies;   a plurality of solenoids, each solenoid mounted for driving a respective one of said dies and including an armature mounted for motion in said transverse direction, each said armature being in contact with the other longitudinal end of said associated die;   means for moving each said armature individually toward said surface from a standby position, said armature driving said associated die against said sheet material, said die flying ballistically toward said material to inelastically deform said material and being stopped only by said sheet material being pressed against said platform surface upon impact by said die, said means for moving including control means for imparting a predetermined longitudinal kinetic energy to each said die of a magnitude sufficient, without substantial excess, to provide said inelastic deformation.   
     
     
       13. The marking system of claim 12 wherein said dies are resiliently biased to abut said armatures. 
     
     
       14. The marking system of claim 12 wherein said dies are spaced from 0.01 to 0.2 inches from said material before energization of the respective solenoid. 
     
     
       15. The marking system of claim 14 wherein said dies are spaced from 0.06 to 0.09 inches from the material before energization of the respective solenoid. 
     
     
       16. The marking system of claim 12 wherein said control means comprises means for applying pulses to each of said solenoids with the duty cycle of each solenoid being less than 2% and the energy dissipated in the respective solenoids during on-time being at least 10 times the continuous rated power dissipation for said solenoids. 
     
     
       17. The marking system of claim 12 further comprising a second row of a plurality of solenoids parallel to and staggered with respect to the first mentioned row and each mounted to drive a separate die, said rows being spaced a distance less than the diameter of each solenoid, said guiding means guiding said strip also in alignment with and spaced from the dies of said second row, and said control means being connected to selectively apply pulses of determined energy to the solenoids of said first and second rows, the dies of said second row being guided to impact the material and dissipate substantially all of the kinetic energy therein in deforming said material. 
     
     
       18. The marking system of claim 12 wherein said control means comprises programmable means for applying said pulses to said solenoids. 
     
     
       19. The marking system of claim 18 wherein said programmable means comprises a computer having a plurality of output ports and being programmed to apply pulses of determinable width to said output ports, and separate driver means for each solenoid coupled to a separate one of said output ports for producing an output pulse to the respective solenoid of an energy that is a determined function of the width of the pulse applied to the respective port. 
     
     
       20. The marking system of claim 19 wherein said driver means comprise means for applying a determined current to the respective solenoid for a time dependent upon the width of the pulse applied to the respective output port. 
     
     
       21. The marking system of claim 12 wherein said control means comprises computer means having a program for selectively energizing said solenoids, the relative number of energizations of each solenoid occurring in a determinable proportion. 
     
     
       22. The marking system of claim 21 further comprising printing means coupled to said computer means for printing out the number of energizations of each of said solenoids. 
     
     
       23. The marking system of claim 12 further comprising means for intermittently advancing said strip for alignment of specific portions thereof with the respective said dies, said means for moving comprising means for producing interrupt signals in response to intermittent movement of said strip, and said control means comprises computer means responsive to receipt of said interrupt signals for energizing determined ones of said solenoids, each said region of said strip being stamped by one and only one of said dies. 
     
     
       24. The marking system of claim 23 wherein said computer means comprises means for calculating which of said dies is to be energized at any position at which said strip is stopped, and means for energizing said solenoids in predetermined relative numbers of energizations.